fix(decorators): async get hits record serializer/size/hit like the sync path (LAB-3765)

src/cachekit/decorators/wrapper.py

@@ -1615,8 +1615,11 @@ async def async_wrapper(*args: Any, **kwargs: Any) -> Any:
                             features.record_cache_operation(
                                 operation="get",
                                 namespace=namespace or "default",
+                                serializer="l1_memory",
                                 success=True,
                                 duration_ms=0.001,  # Sub-microsecond
+                                size_bytes=len(l1_bytes),
+                                hit=True,
                             )
 
                         # Record L1 hit for cache_info()
@@ -1710,11 +1713,18 @@ async def async_wrapper(*args: Any, **kwargs: Any) -> Any:
                     features.record_success()
 
                     if features.collect_stats:
+                        # size_bytes: the encoded envelope, matching the bytes _l1_backfill_from_l2
+                        # stores and the L1 site's len(l1_bytes). A str envelope is UTF-8 encoded
+                        # first, so non-ASCII payloads report byte length, not character count.
+                        _l2_envelope = cached_data.encode("utf-8") if isinstance(cached_data, str) else cached_data
                         features.record_cache_operation(
                             operation="get",
                             namespace=namespace or "default",
+                            serializer="rust",
                             success=True,
                             duration_ms=get_duration_ms,
+                            size_bytes=len(_l2_envelope),
+                            hit=True,
                         )
 
                     # Update L1 cache with the L2 value (serialized bytes) for subsequent

tests/unit/test_async_get_record_labels.py

@@ -0,0 +1,90 @@
+"""Async hit-record stats parity (LAB-3765).
+
+The sync wrapper records an L1 hit as ``serializer="l1_memory", hit=True`` and an L2
+hit as ``serializer="rust", hit=True``, both with the served size; the async L1 and
+uncontended L2 hit sites recorded none of those, so async hits filed under
+``serializer="unknown"``. A miss primes L2 (and L1 via the miss-store); clearing L1
+before the second call forces it past L1 to the L2 site.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Iterator
+from typing import Any
+
+import pytest
+
+from cachekit import cache
+from cachekit.decorators.orchestrator import FeatureOrchestrator
+from cachekit.l1_cache import get_l1_cache_manager
+
+
+class _ByteStore:
+    """Plain in-memory byte store standing in for L2."""
+
+    def __init__(self) -> None:
+        self.store: dict[str, bytes] = {}
+
+    def get(self, key: str) -> bytes | None:
+        return self.store.get(key)
+
+    def set(self, key: str, value: bytes, ttl: int | None = None) -> None:
+        self.store[key] = value
+
+    def delete(self, key: str) -> bool:
+        return self.store.pop(key, None) is not None
+
+    def exists(self, key: str) -> bool:
+        return key in self.store
+
+    def health_check(self) -> tuple[bool, dict[str, Any]]:
+        return True, {}
+
+
+@pytest.fixture(autouse=True)
+def setup_di_for_redis_isolation() -> Iterator[None]:
+    """L1 hygiene between the two cases: tests/unit/conftest.py's no-op override of the root
+    fixture dropped its clear_all(), and a leaked entry would turn the L2 case's priming
+    miss into an L1 hit."""
+    yield
+    get_l1_cache_manager().clear_all()
+
+
+@pytest.fixture
+def recorded(monkeypatch: pytest.MonkeyPatch) -> list[dict[str, Any]]:
+    """Capture the wrapper's explicit features.record_cache_operation(...) calls, keyword args as passed.
+
+    Patched at the orchestrator, not the collector: record_success() also forwards an
+    operation-context record to the collector, which would shadow the labels under test.
+    """
+    calls: list[dict[str, Any]] = []
+    monkeypatch.setattr(FeatureOrchestrator, "record_cache_operation", lambda self, **kw: calls.append(kw))
+    return calls
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("tier", ["l1_memory", "rust"], ids=["l1-hit", "l2-hit"])
+async def test_async_get_hit_records_sync_labels(recorded: list[dict[str, Any]], tier: str) -> None:
+    backend = _ByteStore()
+
+    @cache(backend=backend, ttl=60, namespace="async-get-labels")
+    async def compute() -> dict[str, int]:
+        return {"answer": 42}
+
+    assert await compute() == {"answer": 42}  # miss: primes L2, and L1 via the miss-store
+    assert backend.store
+    if tier == "rust":
+        get_l1_cache_manager().clear_all()  # force the hit past L1 to the L2 site
+    recorded.clear()
+
+    assert await compute() == {"answer": 42}
+
+    gets = [c for c in recorded if c["operation"] == "get"]
+    assert len(gets) == 1
+    assert (gets[0].get("serializer"), gets[0].get("hit")) == (tier, True)  # what the sync hit sites pass
+    # Exact served size, not just positive: both hit sites record the raw serialized
+    # envelope's length — the L1 backfill stores the same bytes L2 returned, so the
+    # single L2 store value is the ground truth for either tier. A `> 0` assertion
+    # would pass on a wrong constant (e.g. size_bytes=1); this pins the real value.
+    expected_size = len(next(iter(backend.store.values())))
+    assert gets[0].get("size_bytes") == expected_size